The OTC has an UR of 2 and can only be used by Heroes, Iceworlders and other suitably awesome persons. A Critical Failure on the Skill check means the OTC hits its user. Anything hit by the OTC loses D6 Structure Points (meaning minifigs are instantly killed).

Remus: Harry... I'm a werewolf.
Harry: Are you fucking serious?
Remus: Well yes, but I don't see how that applies here.

I usually rate OTCs as being about 2d10 when used in melee, and 3d10 and 4d10 when fired from launchers and missile tubes, respectively. Outside of massive 5-inch laser cannons, they're the strongest artillery a unit can field, and certainly the most powerful a single infantryman can use on his own, since they're a Size 1 weapon with a Size 3 or 4 power.

I usually play OTCs as "explosives", because no super death weapon is truly great unless it makes things blow up. They're unwieldy in melee combat, but very well suited as anti-vehicle and area attack weapons. A well-placed shot can cripple a heavy battle tank, or slice an enemy APC into bits.

Of course, OTCs are very unfair weapons, but considering how I only have a handful of them, it still makes conventional weapons necessary. Besides, when is Brikwars ever "fair"?

I think he can beat it, but its also a possibility he would simply vanish into nothing, overtaken by the extreme amounts of uncontrolled awesomeness in his weapon.
on the other hand, its an iceworlder.

- I refuse to be stopped by something as irrelevant as logic, the laws of physics, or common sense -

if 20 chickens can fit in a brick, how many pingpongballs does a crocodile have to eat so it can swim faster than a washing machine?

Maybe, as soon as the OTC is revealed (for the first time) all enemies within 6" of it instantly lose their action. Enemy's in hand to hand combat (range) have a minus modifier to all actions -1 or something. The OTC's damage is the ability to cut through any and all things (Shields, armour, Organic bits or whatever) in a turn. So what the OTC can reach in a sweep is destroyed/cut in two or pierced, up to the physical depth of the OTC. The holder of the OTC gets a boost to their own rolls, the inability to fumble. While they hold the OTC a roll of a one is just that, a one and nothing more.

I personally believe instant wins are awarded only to those players who bring enough Doritos and Pepsi (or doughnuts and beer if Warhead's involved) to sufficiently bribe his opponents into concurring. OTCs should be very powerful, perhaps unfairly so, but not game-breaking powerful. Where's the fun if you win automatically?